Plastic sheets for dental devised have been used for decades. They are heated used an electric grid and then when lowered to the model, a vacuum draws the plastic precisely to the model of the teeth. Indications for use are indirect bonding of orthodontic appliances, orthodontic retainers, mouth guards for sports, and aligners for correcting minor malocclusions. One of the biggest drawbacks is that as that the plastic thins as it is stretched over the plaster model of the teeth causing it to fail quicker, either in occlusion or because of the vacuum force drawing so hard at the outset. This failure can cause hours of extra labor to create a new aligner, as the teeth will have moved since the last impression was taken and the model made, and the doctor or lab must go through the whole process again. Also, it delays the treatment and can lead to relapse if the patient doesn't return immediately. Generally, these sheets are made with a medical grade plastic that severely limits the range of plastic choices. It is this common problem that this patent seeks to correct.